Electric safety device



Aug. 3o, 1927;

c." E. HANNY ELECTRC SAFETY DEVICE Filed 001;.19, 1925 IN VEN TOR.

l l Fn Ch arles .f' H ann y,

Patented Aug. 30, 192.7.

UNITED STATES- PATENT OFFICE.`

CHARLES E. HANNY, OF UNIONVILLE, CONNECTICUT, ASSIGNOR TO yTHE TRUMBULLELECTRIC MANUFACTURING COMPANY, OF PLAINVILLE, CONNECTICUT, A COR-PORATICN F CONNECTICUT.

ELECTRIC SAFETY DEVICE.

Application filed October 19, 1925.

My invention relates particularly to what are commonly termedthermostatic devices. One objectfof the invention is to provide a devicefor automatically opening a circult h in case of overheating.

I have shown a special application of the main invention intended to beused in connection with a motor for feeding oil or similar fuel to aheating or steam operated I device. It is frequently.- necessary toinstall such devices in more or lessinaccessible positions. Sometimesthe thermostat must be mountedon the top of the steam pipe and sometimeson thebottom. Sometimes the 1f pipe may extend vertically and it may benecessary to mount the thermostat on one side of it. Such devices,therefore, must be able to be operated regardless of the pos1- tion inwhich they are mounted.

2" Fig. 11 shows a cross-section of a casingwith a therniostatic deyiceembodying my invention.

Fig. 2 is a plan view showing a part of the vcover of Athe casing brokenaway. iv-i Figu is an end view.

Fig. 4 is a perspective 'View of the thermostatic element by itself.

Fig. 5 isa detailed view of the parts of the thermostatic elementshowing them in the act of separating.

In the form shown, the casing consists of 'i main part 7 which may be'adapted to be :ecured to the side of a pipe, and a cover 8 Ihis covermay be secured in place in v` any suitable ma1iner,"for instance, bymeans of screws 9 which'engage in brackets 10 secured to the outer endof the body 7 of the casing. y y

Vithin the casing is mounted an insulating base of/ porcelain or othersuitable material mo ited upon brackets 12, and se cured, for instance,by screws 13. To this base 11 are secured the spring clips or jaws suchas 14\and 15 to which the terminals of the circuit are connected in anysuitable manner.

The thermostatie element consists of two end members 1G and 17am-d aconnecting piece 18 which may be termed the drop-out. These three piecesmay be of any suitable material such as brass or copper. The two members16 and 17 are preferably in line with each other and the connectingpiece18 is preferably bent into a Zig-zag or Z form Serial No. 63,274.

so that one side of one end of the member 18 is soldered at 19 to oneside of one end of the piece'16, and the opposite side of the piece 18at its opposite end is soldered at 20 to Vthe end of 'the piece 17 onthe side opposite tothe point 19. The solder is of a composition whichwill vmelt quickly at the temperature at which it is desired to have thecircuit automaticallyopened. The

solder may be for instance what is knownas 160 solder. The endv pieces1G and 17 are adapted to be inserted in the spring clips 14 and 15 inthe manner in which an ordinary fuse is inserted in fuse clips. The.Iinsulating'bate 11 is preferably provided with a recess or passage 21between the clips 14 and 15.

By reason of the shape and construction of the parts, the thermostaticelement 18 will automatically fall ordrop out as soon ras the.temperature reaches the melting point of the solder.A The shape andarrangement of thel terminals 16 and 17 and the drop-out member 18 issuch that this automatic open? ing occurs regardless of the position inwhich the parts happen to be mounted. In

Fig. 1 in dot and dash lines I have shown Y' the drop-out fallingvertically through the opening 21. Naturally the solder at one end orthe other will let go a little before the other end. In Fig. 3 I havealso shown the drop-out member 18 falling through the opening 21. InFig. 2 the elements might be considered as mounted horizontally so thatthe strip drops olfv sideways. One of the ends of the member 18beingbelow the member 17, that -end of the member 18 is free to f all withoutobstruction and thus instantly open the circuit. It will be seen thatthis action will take place regardless of the position in which thedevice is located, as soon as lthe temperature has reached the dangerpoint. It does not matter whether' the base carrying the terminalsstands perfectly fiat, upside down, endwise, sidewise, or at any angle;the connecting strip 18 will immediately fall away from the terminalsand break the circuit. Such devices are commonly mounted on the steampipe of n Should the Water get low in thev boiler or for any reason itstemperature gets abnormal, the thermostat will be heated to the pointwhere the solder will melt andallow the element 18V to drop away fromits connections, thus breaking the circuit and stop-- ping the motorautomatically.

Nothing is destroyed, injured or lost in the operation of this deviceexcept that a minute portion of the solder may drop away from/the parts,therefore the parts Vmay be resoldered even by an unskilled workman andit will then be as good as new.

This thermostatic element has the distinct characteristic of operatingat an approximately exact predetermined temperature and the operatingpoint is governed entirely by .necessity of any particular care insoldering and it also obviates the necessity of calibrating or testingthe elements after they are assembled. Another advantage of thisconstruction i that the drop out part 18 is made of comparatively heavybrass or copper and is substantially' equal in conducting capacity tothe lcontact ends 16 and 17, therefore, under normal conditions, itoffers so little eleetricalresistance that it is not at all affected bythe passage of the current.

This thermostat Will operate equally well in the open air or whensubmersed in nonconduoting liquid such as oil. It should be understood,moreover, that the thermostatic element herein shown may be employed instill other relations.

I claim: i 1. A `thermostatic element comprising .a

vfiat zig-zag bent center strip and fiat Contact blades having'substantially the same carrymgcapacity as the center strip, soldered to4`the'endsof the said center strip and adapted to lit into ordinary fuseclips, the contact blade on one end being soldered on the side of saidstrip opposite to the blade on the other end,'the amount of solder beingonly sufficient to hold the parts together.

2. A protective device comprising an insulating base, contact clipscarried by said base and spaced-apart from each other and an assembledthermostatic element detachably carried by said clips and consisting ofI matelythe same cross section as the termina] blades and having itsopposite ends soldered to the opposite sides of said terminal blades andadapted to fall away therefrom regardless of the position of the base.

3. A protective apparatus including an insulatingubase having a passagetherethrough, contact clips mounted at opposite ends oli said passage, aprotective device carried by said clips and consisting of end piecesdetachably mounted in said clips, and a dropout having the oppositesides of its opposite ends sweated to said end pieces, the passage andsaid base being of a relative size to permit the said drop-out to fallthrough the passage. y

4. A protective device includingv an insulating base having an openingtherein, contact clips mounted at opposite ends of said opening, and adrop-out unit detachably secured in said clips, said unit consisting oftwo end members and a central drop-out member sweated to said endmembers at its opposite ends and sides, the said opening in the basebeing large enough to permit the drop-out to pass through the opening insaid base at any relative angle.

5. A protective device includingvan insulating base having an openingtherein, contact clips mounted at opposite ends of said opening, and adrop-out unit detachably secured in said clips, said unit consisting oftwo end members and a central drop-out member sweated toisaid endmembers at its' opposite ends and sides, the said opening in the basebeing large enough to permit the drop-out to pass through the opening insaid `base at any relative angle, and the cross scyother and a readilyreplaceable member consisting of two fiat end blades adapted to bedetachably mounted in said clips and held in definite positions therebyand a flat drop-out member having the oppositeends soldered to oppositesides of the en'd blades, theamount of solder being only suiiicient tounite the adjacent-surfaces of the drop-out member andthe end blades,said end blades being so held that both ends of the drop-out member mustbe released before it can move out position.

CHARLES E. HANNY.

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